Newbie here, waiting on delivery of a 2015 5 door non-S. I've been reading up on minis, and have a concern about direct injection. Does the 1.5 liter engine have a problem with carbon build up on the intake valves? Bobby D.
Welcome, thanks for joining Motoring Alliance, the FUN and Friendly MINI Community. So far there haven't been issues with the new 3 cylinder that we've heard much about at all. It was the previous N14 that was problematic, the later N18 is better. Your's is different than those. Your's is a BMW designed lump used in BMW's as well as MINIs. The previous generation used a Peugeot/BMW design.
Welcome... It is early days for the 3 hole MINI engine. Many makes are having issues with carbon buildup in their direct injection engines. Hopefully MINI has fixed that issue, but if not it is just a service that you do. I wouldn't worry about it.
Welcome! Enjoy the ride! Speaking as someone who has an N14 engine, the carbon buildup issue wasn't as awful as I'd been fearing. I had over 100,000 miles on mine before I had a real issue with it. Some of it can be dealt with by driving habits; avoid frequent sub-20 minute drives and it should be OK. Still, as the others have said, you've got a totally new design that we don't have a lot of experience with. Should be fun learning!
Every generation of GDI engine has been getting better for valve deposits via improved air-oil separators [aka catch cans] in the valve cover. The 1st gen VW FSI's are notorious for bad carbon deposits, as is the MINI/PSA Prince engine, however big wisdom strides in crankcase ventilation have happened since those engine designs and I'd hazard the B38 you'll have in your MINI will be able to go muuuuch further before needing a cleaning. Given OEM's must comply in not venting anything to atmosphere other than the tailpipe, it's also likely that an aftermarket solution [catch can] that simply vents the AOS to atmosphere instead of back into the intake would help carbon build-up at the expense of greater overall vehicle emissions [if you care]. Basically, I wouldn't worry about it. If the engine needs a cleaning every 100k, I would call that acceptable maintenance.